Switches commonly used in communication networks often include a plurality of line cards that are intercoupled by a switching fabric. Each of the plurality of line cards receives ingress data and transmits egress data. The switching fabric allows ingress data received by one card to be directed to an egress connection on one or more of the other line cards included within the communication switch.
Various processing operations are typically performed for the various connections supported by the communication switch. Such connections can include both switched and permanent connections. The processing operations include routing that must occur within the switch such that ingress data received by one line card is directed to the appropriate egress line card. In prior art systems, the processing operations including routing were typically performed by individual processors included in each of the line cards of the communication switch. FIG. 1 illustrates a prior art switch that includes a switching fabric and a plurality of line cards. As is illustrated, each of the line cards includes a processor that is responsible for performing the various call processing and routing functions for connections that are directed through that particular line card.
Such distributed call processing provides some disadvantages that become more apparent as data communication speeds continue to increase. In some cases, specific line cards within the switch will be much more active than other line cards. Some of the more active line cards can become overwhelmed by the amount of call traffic they are required to service. Because of the distributed nature of the call processing amongst the various line cards, a processor on a line card that is not being fully utilized is unable to assist the overburdened processor on another line card. As such, the overall call processing bandwidth available within the switch is not fully utilized.
Another disadvantage of distributed call processing is that none of the processors in the individual line cards has a global perspective on the operation of the switch. As such, the adaptations that an individual processor is capable of performing in order to increase the efficiency of the operation of the switch are limited.
Therefore, a need exists for a communication switch that includes call processing and routing functionality that does not suffer from the disadvantages presented by distributed processing of prior art systems.